PUP-2745 Forge malformed dependency fix

Prior to this commit a malformed name in the dependencies for a downloaded forge
module dependency would cause the PMT to fail unexpectedly.
This commit causes the PMT to ignore malformed dependencies.

Depends on https://github.com/puppetlabs/puppet/pull/2827
Getting rid of username/name, but going to keep repository in hopes that some day we do care because private forge sounds like something that will be important in future versions.